Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd54405e96c5cae9…

MALICIOUS

PDF

73.8 KB Created: 2021-09-24 23:15:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 79a1a5ebcb33c92b38a4f369b2c4c731 SHA-1: ad832b5f5679434ca80fde48c0a9104fb2401d66 SHA-256: dd54405e96c5cae9874503808fd496c543bdd86e2a18ef161f01e04d217abed4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but likely serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://nomylo.ru/uplcv?utm_term=view+ram+usage+android PDF link annotation
    • https://cjsc.se/ckfinder/userfiles/files/15395918667.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/11065461101.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/jodugopaw.pdfIn PDF document text
    • http://timeyear-v.com/userfiles/file/37736600187.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/89789011928.pdfIn PDF document text
    • http://topoint.cc/userfiles/fckFile/20210920185134.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141ce3c02751---duzenomufef.pdfIn PDF document text
    • http://farmina.ru/uploads/files/votafarifuwilukil.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/63289228689.pdfIn PDF document text
    • http://biosystech.com/pdsFck/file/rabusi.pdfIn PDF document text
    • https://ijpdua.com/contents/files/17473244655.pdfIn PDF document text
    • https://gospel-streams.com/asset/ckfinder/userfiles/files/24038671135.pdfIn PDF document text
    • https://www.comperat-89.fr/ckfinder/userfiles/files/sakevasiguvasewe.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/fad02fe4a89930179fcd45ea7f33f72b/57116562146.pdfIn PDF document text
    • http://studio70.eu/userfiles/files/82617812410.pdfIn PDF document text
    • http://ipcmanpower.com/admin/style/images/userfiles/file/65294651310.pdfIn PDF document text
    • http://speckletrack.com/update/editor/file/kebugaf.pdfIn PDF document text
    • http://lamexmarket.com/uploads/files/20687147397.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/nidovujoj.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16140e33eb1292---vurisaxuxok.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/tosepagemaluwiwanavifutom.pdfIn PDF document text
    • https://giaiphapthietke.vn/media/file/files/zelurujukowax.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b7ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7EC 18680 bytes
SHA-256: ad0d48bcae41a062098970e3411f365a28068390e6b9226e42ffb3bb72068bf8
font_01_sfnt_off0000e802.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE802 10600 bytes
SHA-256: 3b365a2ce01b3967eaa336fe6aa693640d8a9eb2fa24b8432374e8599a9c03aa
font_02_sfnt_off00010008.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10008 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1